The invention relates to an air-guiding device for cooling the brakes in a motor vehicle with adjustable air-guiding flaps.
For example, DE 10 2010 037 615 A1 discloses an air-guiding device with adjustable flaps for optionally cooling an internal combustion engine or the brakes in a motor vehicle. The radiator discharged air from the engine compartment is used for cooling. The cooling of the brakes depends, in particular, on the intensity and duration of the braking intervention or the temperature of the brake discs. Usually, what is referred to as a temperature model, which takes into account a multiplicity of parameters, is used for this and is stored in a control unit for controlling the flaps.
The object of the invention is to simplify an air-guiding device for cooling the brakes.
This and other objects are achieved according to the invention by an air-guiding device for cooling the brakes in a motor vehicle having adjustable air-guiding flaps and an electronic control unit for controlling the air-guiding flaps as a function of vehicle speed and as a function of pilot control pressure generated in the brake system due to the activation of the brake pedal. A first mode and a second mode for opening the air-guiding flaps are provided in the control unit by way of a corresponding program module. The first mode is designed for a strong deceleration demand at a relatively high vehicle speed, and the second mode is designed for an acceleration prevention demand at a relatively low vehicle speed.
Basically, the air-guiding device according to the invention for cooling the brakes has adjustable air-guiding flaps and an electronic control unit for controlling the air-guiding flaps as a function of the vehicle speed and of the pilot control pressure in the brake system, generated by the activation of the brake pedal. In the control unit, a first mode and a second mode for opening the air-guiding flaps are provided by way of a corresponding program module. The first mode is designed for a strong deceleration demand at a relatively high vehicle speed, in particular on freeways and country roads. The second mode is designed for an acceleration prevention demand at a relatively low vehicle speed, in particular when travelling downhill on roads through mountain passes.
Since the air resistance is worsened and the fuel consumption is increased when the flaps are opened, the invention cools the brakes only in the case of increased demand. Furthermore, only two operating parameters for the flap controller are used, as a result of which the method can be implemented very easily and in a robust fashion.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawing.